BitTorrent Inc. has announced several new features for its free Sync app, which moves out of alpha today. Since its first release in April the secure Dropbox alternative has gathered a healthy spread of users, who to date have shared eight petabytes of data. Based on feedback from early adopters, BitTorrent is rolling out support for Android as well as an archive folder which stores previous versions of synced files.

Dropbox, Google Drive and Microsoft Skydrive are just a few examples of the many file-storage and backup services available today.

All these services have a major drawback, as they rely on external cloud-based hosting to back up and store files. This means that not only do you have to trust these companies with your personal and confidential files, but free storage space is limited.

BitTorrent Sync is a new backup tool that eliminates these drawbacks, and it’s much faster too. The functionality of the Sync application is comparable to most cloud-based sync tools, except for the fact that there’s no cloud involved.

Users simply share their files across their own devices, or the devices of people they invite to their private folders.

Today BitTorrent Inc. has moved Sync’s status from alpha to beta. The San Francisco company is developing the product at a rapid pace and is already seeing a massive demand from users who have shared eight petabytes of data so far.

While Sync is an entirely new product, it is based on the uTorrent code base which has proven its value to millions of users.

In recent weeks Sync has been upgraded with some smaller features including one-way synchronization and one time secrets. With the new beta, BitTorrent Sync expands further with support for Android devices, and an archive feature that allows users to access previous versions of synced files.

The Android version allows users to sync files from a mobile device to a computer, and vice versa. In addition it supports quick ad-hoc BitTorrent sharing between two mobiles or tablet.

Like its Windows and Mac-based applications, the Android app is available without charge, and BitTorrent Inc. informs us that it will remain free in the future. Eventually the company may launch premium features to monetize the service.

“The basic Sync functionality – that is to say all of the features being made available as of today – will remain free to use,” a BitTorrent spokesman told TorrentFreak.

“We are exploring potential business models which may include premium features to address certain applications. For example, enterprise, where we have the potential to offer significant cost savings and added security and speed benefits.”

It will be interesting to see how Sync evolves, but as the public grows more skeptical of the privacy vulnerabilities of cloud services, we expect there to be a healthy demand. Interested? The latest beta version is available in the BitTorrent labs.